APL in the obese: Should we treat it differently?

Background

Differentiation syndrome (DS) is a life-threatening complication in acute promyelocytic leukemia (APL). Studies have reported that a high body mass index (BMI) is the most powerful predictor of DS, with an odds ratio of 7.24.1,2 At the 2017 International Symposium on APL, a case study was presented which further examined this relationship.3

Study design

Eighteen patients with low- to intermediate-risk APL received induction therapy with all-trans retinoic acid and arsenic trioxide according to the GIMEMA protocol on an in-patient basis in the last two years.

The two most difficult cases to manage during induction were obese patients (BMI >30).

Case 1 was a 25-year-old male with intermediate-risk APL and a BMI of 33 kg/m2.

Case 2 was a 52-year-old female with intermediate-risk APL and a BMI of 31 kg/m2.

Key findings

Baseline characteristics and clinical summaries of the obese and non-obese patients are summarized in Table 1.

Both obese patients died of DS. Their disease progressions are summarized in Figure 1.

Table 1. Clinical summary and results

Figure 1. Event chart

Key conclusions

The association of obesity with DS has important clinical implications.

More intense DS prophylaxis might be necessary in obese patients during induction.

Aggressive correction of increased leukocyte count with anthracyclines should be considered earlier in obese patients.

Urgent initiation of therapeutic dosing of steroid at the earliest clinical suspicion of DS may be effective.